1. R. W. Hertzberg andJ. A. Manson, “Fatigue of Engineering Plastics” (Academic Press, New York, 1980) p. 160.
2. M. K. V. Chan andJ. G. Williams,Polymer
24 (1983) 234.
3. A. Lustiger andR. D. Corneliussen,J. Mater. Sci.
22 (1987) 2047.
4. N. Brown andX. Lu, “The Kinetics and Microscopic Processes of Long Term Fracture in Polyethylene Piping Materials”, GRI-88/0135 Report, Gas Research Institute, 8600 West Bryn Mawr Ave., Chicago, Illinois 60631, USA.
5. A.W. Heston, MS thesis, Department of Mech. Eng. and Appl. Med., University of Pennsylvania (1983).